It is possible that all the nodes you knew at the time are now gone. This happens a lot with dynamic IP addresses, where nodes move around their ISP's IP pool. To try to fix it: exit monerod, delete the p2pstate.bin file (in ~/.bitmonero, search for it if you're on Windows), restart monerod, wait up to a minute.

I deleted this file and restarted. I let it run for white a while but saw no new blocks downloaded. Here is the terminal output for monerod:

Thanks,

Perazim

yossi@nuc-i3:~$ ./monerod 2017-08-20 12:59:18.477 7fc889bc9ec0 INFO global contrib/epee/src/mlog.cpp:145 New log categories: *:WARNING,net:FATAL,net.p2p:FATAL,net.cn:FATAL,global:INFO,verify:FATAL,stacktrace:INFO 2017-08-20 12:59:18.478 7fc889bc9ec0 INFO global src/daemon/main.cpp:282 Monero 'Wolfram Warptangent' (v0.10.3.1-release) 2017-08-20 12:59:18.478 7fc889bc9ec0 INFO global src/daemon/protocol.h:55 Initializing cryptonote protocol... 2017-08-20 12:59:18.478 7fc889bc9ec0 INFO global src/daemon/protocol.h:60 Cryptonote protocol initialized OK 2017-08-20 12:59:18.478 7fc889bc9ec0 INFO global src/daemon/p2p.h:63 Initializing p2p server... 2017-08-20 12:59:22.603 7fc889bc9ec0 INFO global src/daemon/p2p.h:68 P2p server initialized OK 2017-08-20 12:59:22.603 7fc889bc9ec0 INFO global src/daemon/rpc.h:58 Initializing core rpc server... 2017-08-20 12:59:22.603 7fc889bc9ec0 INFO global contrib/epee/include/net/http_server_impl_base.h:70 Binding on 127.0.0.1:18081 2017-08-20 12:59:22.603 7fc889bc9ec0 INFO global src/daemon/rpc.h:63 Core rpc server initialized OK on port: 18081 2017-08-20 12:59:22.603 7fc889bc9ec0 INFO global src/daemon/core.h:73 Initializing core... 2017-08-20 12:59:22.606 7fc889bc9ec0 INFO global src/cryptonote_core/cryptonote_core.cpp:326 Loading blockchain from folder /home/yossi/.bitmonero/lmdb ... 2017-08-20 13:06:45.556 7fc889bc9ec0 WARN net.dns src/common/dns_utils.cpp:531 WARNING: no two valid MoneroPulse DNS checkpoint records were received 2017-08-20 13:06:45.567 7fc889bc9ec0 INFO global src/daemon/core.h:78 Core initialized OK 2017-08-20 13:06:45.567 7fc889bc9ec0 INFO global src/daemon/rpc.h:68 Starting core rpc server... 2017-08-20 13:06:45.567 [SRV_MAIN] INFO global src/daemon/rpc.h:73 Core rpc server started ok 2017-08-20 13:06:45.568 [SRV_MAIN] INFO global src/daemon/p2p.h:78 Starting p2p net loop... 2017-08-20 13:06:46.568 [P2P1] INFO global src/cryptonote_core/cryptonote_core.cpp:1098

---

The daemon will start synchronizing with the network. It may take up to several hours.

You can set the level of process detailization* through "set_log <level|categories>" command*, where is between 0 (no details) and 4 (very verbose), or custom category based levels (eg, *:WARNING)

Use the "help" command to see the list of available commands.

---

2017-08-20 13:06:49.829 [P2P1] WARN net.dns src/common/dns_utils.cpp:531 WARNING: no two valid MoneroPulse DNS checkpoint records were received 2017-08-20 13:06:51.244 [P2P1] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [91.203.224.198:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380685 [Your node is 72772 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:10:00.589 [P2P8] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [140.112.93.38:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380686 [Your node is 72773 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:11:05.826 [P2P4] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [83.212.103.13:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380688 [Your node is 72775 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:12:08.919 [P2P3] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [101.100.161.72:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380689 [Your node is 72776 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:16:11.484 [P2P6] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [46.0.45.253:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380690 [Your node is 72777 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:17:18.520 [P2P3] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [95.215.19.16:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380691 [Your node is 72778 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:20:44.743 [P2P2] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [82.155.204.176:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380692 [Your node is 72779 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:22:10.926 [P2P8] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [45.76.151.131:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380693 [Your node is 72780 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:24:27.682 [P2P8] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [120.147.202.182:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380694 [Your node is 72781 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:25:33.908 [P2P9] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [195.24.148.10:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380695 [Your node is 72782 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:26:38.443 [P2P1] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [174.138.52.90:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380696 [Your node is 72783 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:29:18.207 [P2P7] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [24.21.96.61:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380697 [Your node is 72784 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:30:17.508 [P2P7] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [209.6.43.2:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380698 [Your node is 72785 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:31:48.238 [P2P5] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [194.247.13.160:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380700 [Your node is 72787 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:35:12.182 [P2P8] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [24.90.0.208:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380702 [Your node is 72789 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:36:06.192 [P2P9] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [188.243.69.182:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380704 [Your node is 72791 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:36:21.363 [P2P6] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [46.246.35.204:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380705 [Your node is 72792 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:39:49.580 [P2P8] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [107.150.60.162:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380706 [Your node is 72793 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:42:29.609 [P2P0] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [67.41.40.110:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380707 [Your node is 72794 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:45:27.132 [P2P7] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [84.242.119.147:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380708 [Your node is 72795 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:47:29.762 [P2P2] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [70.123.22.15:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380709 [Your node is 72796 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:48:58.308 [P2P2] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [144.217.45.34:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380710 [Your node is 72797 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:50:00.151 [P2P0] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [176.9.140.62:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380711 [Your node is 72798 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:52:00.134 [P2P8] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [24.124.124.4:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380716 [Your node is 72803 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:52:54.210 [P2P9] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [51.15.129.173:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380717 [Your node is 72804 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 13:57:57.272 [P2P9] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [71.163.165.248:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380718 [Your node is 72805 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:01:02.958 [P2P0] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [87.98.217.187:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380721 [Your node is 72808 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:04:48.854 [P2P0] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [78.130.219.75:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380723 [Your node is 72810 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:07:01.613 [P2P7] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [76.69.198.96:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380724 [Your node is 72811 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:07:19.728 [P2P6] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [73.193.228.115:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380725 [Your node is 72812 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:11:16.629 [P2P0] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [219.85.89.43:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380726 [Your node is 72813 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:12:48.925 [P2P9] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [58.18.7.251:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380727 [Your node is 72814 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:13:32.787 [P2P9] INFO global src/cryptonote_protocol/cryptonote_protocol_handler.inl:293 [195.154.182.94:18080 OUT] Sync data returned a new top block candidate: 1307913 -> 1380728 [Your node is 72815 blocks (101 days) behind] SYNCHRONIZATION started 2017-08-20 14:13:52.856 [P2P7] INFO global src/cryptonote_protocol/cryptonote_protocol_handler

Found the problem. Had to lower the block-sync-size from the default of 200 to 20. I have a slower net connection of 2mb/s.